Liquid crystal was discovered by the Austrian botanist Fredreich Rheinizer in 1888. "Liquid crystal" is neither solid nor liquid
(an example is soapy water).
In the mid-1960s, scientists showed that liquid crystals when stimulated by an external electrical charge could change the properties of light passing through the crystals.
The early prototypes (late 1960s) were too unstable for mass production. But all of that changed when a British researcher proposed a stable, liquid crystal material (biphenyl).
Today's color LCD TVs and LCD Monitors have a sandwich-like structure
TFT LCD (Thin Film Transistor Liquid Crystal Display) has a sandwich-like structure with liquid crystal filled between two glass plates.
TFT Glass has as many TFTs as the number of pixels displayed, while a Color Filter Glass has color filter which generates color. Liquid crystals move according to the difference in voltage between the Color Filter Glass and the TFT Glass. The amount of light supplied by Back Light is determined by the amount of movement of the liquid crystals in such a way as to generate color.
A TFT monitor uses thin-film transistor technology for the ultimate LCD display. LCD monitors, also called flat panel displays, are replacing the old style cathode ray tubes (CRTs) as the displays of choice. Nearly all LCD monitors today use TFT technology.
The benefit of a TFT monitor is a separate, tiny transistor for each pixel on the display. Because each transistor is so small, the amount of charge needed to control it is also small. This allows for very fast re-drawing of the display, as the image is re-painted or refreshed several times per second.
Prior to TFT, passive matrix LCD displays could not keep up with fast moving images. A mouse dragged across the screen, for example, from point A to point B, would disappear between the two points. A TFT monitor can track the mouse, resulting in a display that can be used for video, gaming and all forms of multimedia.
A typical 17-inch TFT monitor has about 1.3 million pixels and 1.3 million transistors. That leaves a significant chance for a malfunctioning transistor or two on the panel. Upon delivery, a TFT monitor can have "dead pixels" for this reason. A dead pixel is a pixel whose transistor has failed, thereby creating no display image. On a solid black background, dead pixels will stand out as tiny dots of red, white or blue. Most manufacturers will not replace a TFT monitor that has less than 11 dead pixels. Often, a TFT monitor won't have any dead pixels —- always the hope for any buyer, though dead pixels are not noticeable unless located in a critical position on the screen.
There are only a handful of TFT factories that turn out panels for all brands of TFT monitors. Since there is a given failure rate -- considering how many transistors are on each panel -- only so many of the displays come out bearing no dead pixels, while a certain percentage bear an acceptable number of dead pixels and other panels are unusable. The panels that bear some dead pixels are often sold to be used in discount models. If looking for a TFT monitor, it is a good idea to read feedback provided by buyers at popular online retail sites. By scanning the reviews for several brands, it is easy to get a feel for which models have consistently good panels that rarely bear dead pixels.
A TFT monitor delivers crisp text, vibrant color and an improved response time for multimedia applications. If interested in gaming, video editing or other multimedia applications, look for a TFT monitor with a response rate of 16ms or less.
Answered by
Om Prakash
, an ibibo Master,
at
8:26 PM on June 11, 2008
